Rotary drilling machine and pipe tongs



Nov'. 28, 1939. H c. HICKS 5 ROTARi DRILLING MACHINE AND RIPE TONGS Filed Aug. 15, 1958 2 SheetsSheet-l HA'ROLD c. HICKS /Nl EN7'OR Nam 28, 1939. Hhc. HlCKS I ROTARY DRILLING MACHINE AND PIPE TONGS .F'iied Aug. 15, 1958 2 Sheets-Sheet 2 RM mw, WW wDJ o w R A H A TTORNEV Patented Nov. 28, 1939 ROTARY DRILLING MACHINE AND PIPE TONGS Harold C. Hicks, Taft, Calif.

Application August 15, 1938, Serial No. 224,949

3 Claims.

The object of the invention is to provide apparatus by the use of which the so-called rotary drilling of wells may be performed more expeditiously and with less labor than is possible with apparatus heretofore known.

In the art of drilling deep wells by the rotary method, the drilling bit is rotated on the bottom of the hole by means of a drill string; a string of heavy walled pipe of which the individual lengths or joints are made up by means of threaded collars. In present practice this drill string is rotated by means of a rotary table supported by the derrick floor adjacent the wellhead. This table is essentially a large bevel gear driven by suitable means and having a square hole centrally disposed, this hole engaging an elongated member of square section, known as the kelly. The lower end of the kelly is threaded to fit the threads of a drill pipe collar, the kelly thus forming the upper end of the drilling string and driving it. As drilling proceeds the pipe feeds downward of its own weight, or such portion of its weight as is left unbalanced, the kelly sliding through the square opening in the table, which is kept in continuous rotation.

When drilling has progressed for a distance I equal to the available length of the kelly, the latter is disconnected and one or more joints of pipe added to the string. At intervals, for replacement of the bit and other purposes, the entire drilling string is withdrawn, broken into "stands equal in length to the free height within the derrick, and later replaced in the hole. In these various connecting and disconnecting operations the joints are broken and made up by means of tongs or wrenches which are moved into place and clamped around the pipe when needed, these tongs being as a rule suspended, moved and actuated by power taken from suitable points in the drilling mechanism but being manipulated by hand. Because of their great weight the manipulation of these tongs is tedious and hazardous, and a considerable proportion of the total drilling time is used in breaking and making up pipe connections.

The apparatus herein described eliminates the kelly and also the tongs, elements mounted on the table itself driving the pipe in a right hand (clockwise) direction while drilling and while making up joints, and in a left hand direction for breaking joints.

The apparatus of my invention is shown in an illustrative and exemplary manner in the attached drawings, in which:

Fig. 1 is a view in elevation of the assembled apparatus, the derrick structure within which it is placed being omitted;

Fig. 2 is a plan view of thetable generally indicated at I2 of Fig. 1, parts being broken away to show internal structure, and

Fig. 3 is a vertical section as'on the line 33 of Fig. 2.

Referring to the drawings, I is a fragment of the drill pipe, which in this'instance is provided with external collars as at H. Surrounding the drill pipe, and shown generally at I! in Fig. 1, is the combined rotary table and tongs, shown in greater detail in Figs. 2 and 3. Mounted on this table are the pipe gripping dogs l3l3, which are shaped in the manner shown in Fig. 2. In plan, each of these dogs is a symmetrical, six sided figure, of which the toothed inner sides are arcs of circles of substantially the same radius as the outside of the drill pipe, the outer smooth sides are arcs of a larger circle, and the ends, shown as being straight, may be of any form. It is preferred that the ends join the outer faces in arcs of small circles.

The table is provided with a plurality of these dogs, preferably three and never less, each dog lying in one of the bays "-44, which bays form the central opening in rotating table I5. The

bays are bounded by circular arcs of the same radius as those forming the outer faces of the dogs l3, these arcs being so disposed that when one of the toothed inner faces of a dog engages the outer surface of the pipe, the arcuate outer surface of one half of the dog will coincide in position with the corresponding inner surface of the bay in which the dog is located. With this arrangement, when table I5 is rotated clockwise (as represented in Fig. 2) the opposed dogs will be forced inwardly bysliding over the inner surface of the bays and will thus be caused to firmly grip the pipe, and to rotate the pipe in this direction so long as the table is revolved.

The table proper, l5, carrying the dogs, is rotated by a pinion l6 and square shaft II in a manner which will be more fully described hereinafter.

Table I5 is mounted within a housing I8 which, as will be described, is prevented from rotating but is vertically movable. suitable-antifriction means |9--l9, which may be rings of balls or rollers, permit the table to revolve within the housing. A cover plate 20, bolted to the housing, prevents the table from riding up and out of its normal position. A friction spider 2|, resting at its downturned edges on table I5, is held in place by a recessed upper cover plate 22 which in turn is bolted to plate 20.

The arms of the spider, which correspond in number and position with dogs l3, are provided with radial slots 23-23 which loosely engage studs 24-24, one of which is projected upwardly from a more or less central position on the upper surface of each dog. A tension spring 26, having its inner end attached to one of these studs and its outer end to the rim of the spider, tends to draw the dog outwardly and thus away from the pipe.

Bent spring members 25-25, of which any number may be used, are placed between the rim of 'the spider and the inner face of the recess in upper cover plate 22. These spring members, while permitting continuous rotation of the spider with the table and within the housing, tend by their frictional engagement with the cover plate to cause a limited retardation of this movement, that is to say, a rotation in the reverse direction as regards the table.

The function of the spider and its associated parts will be evident from the following description of its operation. In Fig, 2, dogs l3 are shown engaged with the pipe for clockwise rotation. If now the direction of rotation of the table be reversed, spider 2! will not immediately partake of this reversed rotation, being restrained by the friction of springs 25 against the stationary housing. As studs 23 project into the slots in the spider, the dogs will temporarily be held against rotation and the inner face of the bay I l will move away from the outer face of the dog, permitting tension spring 2G to draw the dog outwardly and out of contact with the pipe. If this left hand movement be continued, the outer face of the dog will encounter the opposed inner face of the bay and ride up on it until the dog is forced into counterclockwise engagement with the pipe, after which the spider begins and continues to rotate with the table and within the housing.

It will be seen that in this manner the engagement of the dogs with the pipe for rotating it in either direction is produced by a mere rotation of the table around the pipe through a slight distance, and that the dogs may be retracted entirely from the pipe by terminating this rotation of the table at the point where the dogs rest in the bottoms of the bays. If the drill pipe used is provided with outside collars, as is usually the case, the bays should be of such depth that when the dogs are fully retracted they will freely pass over the collars.

Table I5 may be centered in the housing by any preferred means, such for example as flanges projected downwardly from the table and up wardly from the bottom of the housing, but in the drawings is shown as being centered by means of a plurality of idler pinions 21 spaced about the toothed periphery of the table and revolving on suitable pins fixed in the housing. The table is revolved by means of a pinion such as l6, suitably supported in the housing and driven by a square, splined or feathered shaft I! which in turn is revolved by any source of power not shown. In the drawing Fig. 1 the drive is shown as transmitted through bevel gears 28 from a horizontal shaft 29. The power unit must include suitable gears or other means for reversing the driving direction at will,

The housing is restrained against rotation by arms carrying bearing sleeves 3U3ll which are slidably fitted on pillars 3l-3l, these pillars being rigidly supported in a vertical position by the derrick structure not shown. Any desired portion of the weight of the assembly i? may be counterbalanced as by weights 32, but a portion of the weight should be left unbalanced to permit the assembly to be lowered when free from the pipe. The assembly may be raised and lowered by means of a cable 33 passing to any convenient hoisting means, such as the calf wheel drum.

In drilling with the above described device,

the entire assembly is raised to such height as the length of the pillars will permit and table is rotated right hand to engage the dogs with the pipe and cause its rotation in the drill ing direction. During drilling the assembly feeds downwardly with the pipe, which is supported by the conventional swivel and travelling bloclr, only the kelly being omitted. In this operation pinion l6 slides downwardly on the square shaft H, For setting up or breaking out individual joints or stands of pipe the assembly is lowered to some convenient position adjacent the derrick floor, the pipe in the hole being restrained against rotation by suitable spiders or fixed tongs,

As above described, the apparatus is used both for drilling and for making up and disconnecting, the usual rotary table and kelly being omitted. If preferred, drilling may be conducted in the conventional manner and the equipment above described used only for making and breaking joints, in which use it may be fixed above the conventional rotary table in any convenient position. By the use of this apparatus a large part of the time required for running into out of the hole and for adding pipe while drilling, as well as a considerable amount of labor, may be saved, and the hazard incidental to the use of the live tongs may entirely be avoided.

It will be understood that the drawings and description are illustrative only and. that the scope of the invention is limited solely by the appended claims.

I claim as my invention:

1. Apparatus for rotating drill pipe. comprising: a rotatable table having a central opening formed with inwardly curved bays, arranged to surround said drill pipe; means for rotating said table in either direction at will; a housing supporting'said table and means for preventing rotation of said housing; a plurality of pipe-gripping dogs surrounding aid pipe and mounted in said bays, said dogs-being provided with projecting studs; and a spider having radial slots en gaging said studs and provided with frictioncreating means arranged to resist rotation of said spider within said housing.

2. Apparatus substantially as and for the pur-- pose set forth in claim 1, in which said spider is adapted to maintain the angular spacing of said dogs one from another substantially constant.

3. Apparatus for rotating drill pipe, comprising: a roiatable table having acentral opening formed with a plurality of similar bays, said bays being bounded by surfaces of revolution non-coax al with said tableso arranged that in each bay the distance from the axis of said table to the boundary of said bay increases gradually from both ends of the baytoward the middle of said boundary; dogs mounted in said bays haw ing inner surfaces adapted to grip said pipe and outer surfaces arranged to fit the surfaces of said bays and to slide upon them; means for holding said dogs in contact with the surfaces of said bays; means for rotating said table in either direction at will; and means tending to restrain said dogs from rotating with said table, whereby rotation of said table in either direction will urge said dogs into pipe-engaging position and ther after cause said pipe to rotate in unison with said table and whereby, said dogs being engaged by rotation in one direction, limited rotation in the other direction will retract said dogs from pipe-engaging position.

HAROLD C. HICKS, 

